Long-term Monocular Deprivation during Juvenile Critical Period Disrupts Binocular Integration in Mouse Visual Thalamus

SUMMARY During development, neural circuits are particularly vulnerable to change by altered sensory experience. For example, monocular deprivation (MD) during the critical period leads to long-lasting changes in ocular dominance and spatial acuity in the visual cortex. The site of action has been widely considered to be cortical. However, recent evidence indicates that binocular integration may first occur in the dorsolateral geniculate nucleus of the thalamus (dLGN), leaving open the question of whether changes in early visual experience can affect binocularity in dLGN. Using in vivo two-photon Ca2+ imaging of dLGN afferents in superficial layers of visual cortex in mice, we demonstrate that critical-period MD leads to a selective impairment of binocularity in dLGN inputs while visual acuity in this pathway remains relatively intact. Our data suggest that the ocular dominance changes following critical-period MD may partially reflect binocularity loss in dLGN neurons.